1. Field of the Invention
This invention relates generally to surgical instrumentation and, more particularly, to a surgical retractor adapted for percutaneous introduction in performing examinations or surgical procedures within body cavities.
2. Description of Related Art
During surgery, the function of holding tissue and organs in a given location to facilitate access and viewing is typically accomplished by a retractor. This instrumentation is ordinarily in the form of a broad paddle structure or multiple fingers attached to a handle. See, for example, U.S. Pat. No. 3,467,079 (James).
Endoscopic or laparoscopic procedures are characterized by the provision of an elongated cannula structure or trocar having a relatively small diameter with a proximal and distal end. The distal end is passed through the surrounding tissue into the body cavity via an incision in the body cavity. The trocar provides a conduit for the insertion of surgical instrumentation.
Collapsible intralumen expanders or retractors for endoscopic procedures have taken the form of radial fingers which are activatable to extend relative to each other upon entering the body cavity. A device for accomplishing such a task is disclosed in U.S. Pat. No. 5,195,505 to Josefsen. This patent describes a retractor structure showing a plurality of retractor blades mounted in a tubular housing. The blades are moveable between a closed position and an open position to facilitate ease of insertion and deployment through a trocar.
However, such endoscopic procedures are amenable to improvement. For example, each device in the endoscopic or laparoscopic procedure requires the use of a conventional trocar. The number of trocars that may be used during an operative procedure is limited in order to provide an uncluttered operating site, thereby minimizing available instrument access.
Percutaneous insertion techniques have been created in order to manipulate internal tissue where access to the body cavity is to be achieved through a very small percutaneous incision or puncture without necessitating the use of a trocar. For example, U.S. Pat. No. 5,106,369 (Christmas) discloses a needle instrument used with a flexible steel wire slidable within the needle. The flexible wire is provided with an atraumatic memory curved end which forms a hook upon being extended from the needle. The hook portion is employed to cradle and stabilize the umbilical cord and to permit the performance of various medical procedures on the umbilical cord. The distal end of the wire has an atraumatic tip to inhibit the puncture of the umbilical cord or other tissue.
However, this percutaneous structure is associated with a possibility of coring tissue upon insertion and the tissue thus removed may block the needle lumen and inhibit the deployment of the flexible wire.
There is, accordingly, a need for a new and improved surgical retractor to overcome the shortcomings and drawbacks of the above-mentioned prior art apparatus.